The invention relates to a device for producing wrapped pressed bales, in which a material which can be pressed is present, having a pressing device which is arranged so as to be movable vertically and which is provided with at least one rotatable tapered compressor roller, having a receiving device which is constructed in the form of an open cylindrical hollow body for receiving the material to be pressed, and having a base platexe2x80x94closing the receiving device towards the bottom and arranged so as to be detachable from the receiving devicexe2x80x94for supporting the pressed bales.
It is known to press bulk materials or plant materials, or even refuse, into pressed bales and to wrap them with a viscoplastic foil for the purpose of storage and/or transportation.
EP 0 106 268 A1 should be mentioned as the closest prior art. This publication describes a device for compressing packaging material and easily pressable waste in a cylindrical container open at the top. In this device it is provided that a centrally arranged and vertically extending shaft is arranged on an arm of a stand engaging over the container, at least one support, which extends horizontally and on which a compressor roller is rotatably mounted, being provided at the lower end of the said shaft, and the compressor roller resting on the refuse by virtue of its own weight. Because of the rotation of the shaft the compressor roller rolls on a circular path on the refuse to be pressed, in which case the compressor roller and the shaft are moved upwards accordingly as the pressed layer of refuse increases. When the pressing procedure has finished, a pressed bale is formed which has not been wrapped. This means that with this device it is possible to press only those materials or substances which do not fall apart again on account of their structure after the pressing procedure. Refuse is a typical example of this. If, on the other hand, it is desired to press bulk materials or, for example, plant materials chopped into small pieces, limits would be encountered very quickly, since at least partial quantities of the pressed material would become detached from the pressed bales or the latter would even fall apart again during the transportation of pressed bales of this type at the latest.
On the basis of this prior art, the object of the invention is further to develop a device of the type defined in the introduction in such a way that it is suitable for pressing materials of widely different types. In this case it should be possible to set the device to be produced with a view to optimizing the pressing procedure to the materials to be pressed. The device should allow the pressed bales to be wrapped with foil, without the production procedure of the pressed bales being delayed.
The object is attained in that the receiving device and the base plate are mounted so as to be rotatable about a common vertical axis, the base plate can additionally be moved in the vertical direction, and a winding device provided with at least one winding head is arranged in such a way that at the beginning of the winding procedure the at least one winding head is situated at the level of the common connexion area of the receiving device and the base plate.
The essential advantage of the invention is that the manner of operation of the proposed device can be set to the physical properties of the material to be pressed. This can be achieved in particular on account of the fact that the receiving device, the base plate and the compressor rollers can be rotated independently of one another. As a result, different operating states can be set up with the possibility of devising and applying the optimum pressing procedure for a specific material. In the case of awkwardly shaped materials, such as occur for example in refuse, the receiving device and the base plate will be allowed to rotate more slowly than in the case of chopped-up plant material. In this case, solely because this material can be supplied more uniformly to the receiving device, the receiving device and the base plate can be rotated more rapidly. It is not absolutely necessary, however, for the receiving device and the base plate to be moved in synchronism, but the receiving device can even be at a standstill when it is used to optimize a pressing procedure. Even the rotational movements of the compressor rollers can be selected differently. It has also been found to be advantageous if the pressed bale can be pressed out downwards out of the receiving device, in which case the winding device is activated at the same time and the pressed bale is progressively wrapped with foil by the winding head. It has likewise been found to be advantageous to keep the winding head in readiness at that level at which the wrapping of the pressed bale can begin immediately after the pressing procedure is concluded. As a result, no valuable time is lost during the production process.
The invention allows further advantageous embodiments. In this way it is possible, in addition to the possibilities of variation just mentioned, also to select the pressing forces of the pressing device to be at different degrees. In particular, in the case of delicate material, for example material such as is provided as animal feed, the pressing forces will be kept low. In the same way it is possible to operate at high pressing forces when the material to be pressed, such as refuse, also permits forces of this magnitude. Pressed bales can then in fact be produced which have a very high density and so equal units of volume of material to be pressed require correspondingly less space.
In accordance with a further embodiment of the invention it is recommended to arrange the longitudinal axis of the at least one tapered compressor roller so as to be inclined from the outside to the inside, so that each compressor roller can be moved with its outer end-face boundary to close to the inner wall of the receiving device. In this case it has been found to be useful if, when at least two compressor rollers are used for example, one of the rollers is longer than the other compressor roller and the longer roller extends beyond the vertical axis of the receiving device as viewed from above. In this way, no area remains unpressed in the centre when the base plate is rotating on the pressed bale.
Finally, in accordance with a third embodiment it is likewise advantageous, not only for a sweeping means to be provided on the at least one compressor roller, but likewise for a further sweeping meansxe2x80x94which extends in the vertical direction and which is used to sweep the inner wall of the receiving device and thus to keep it cleanxe2x80x94to be arranged on the pressing device.